Biopsy needle with integrated guide pin

ABSTRACT

A biopsy instrument for use in a biopsy gun includes a hollow outer needle defining a lumen therethrough and an inner needle slidably engaged within the lumen. The inner needle defines a cavity adjacent its distal end for receiving a tissue sample. A first hub is attached to the proximal end of the inner needle, and a second hub is attached to the proximal end of the outer needle. An elongated pin having a first end and a second end is fixedly attached to the first hub at the first end of the pin. The second end is in contact with the second hub so that the hub and pin are slideable relative to each other. A stop engagement between the second end of the pin and the second hub is configure to prevent disengagement of the needles and to maintain a specific physical relationship between the hubs.

FIELD OF THE INVENTION

The present invention relates to an improved biopsy needle suited foruse in a biopsy gun, or for use as a surgical instrument.

BACKGROUND OF THE INVENTION

Biopsy needles, as part of a biopsy system, are generally used in themedical field to remove tissue, cells or fluids from a body forexamination. Known biopsy needles have at least one inner needle(stylet) and an outer needle (cannula). The stylet has a point to enableinsertion of the needle into a body, and a recess or notch located nearits distal end for receiving a tissue sample. The cannula isdisplaceably guided on the stylet and has sharp cutting edges. Both thestylet and cannula have a connecting element on their proximal ends toenable connection of the needle to the slides of a biopsy gun. Theconnecting elements in known biopsy needles generally have includedeither flanges that cooperate with matching contact surfaces on theslides, or recesses that engage a rib located on a slide wherein boththe slide and the rib run along the length of the biopsy needle.

Some prior art biopsy needles have the disadvantage that it is sometimesdifficult to insert them into the biopsy gun under sterile conditions.Some prior art biopsy guns require a certain spacing between theconnecting elements on the stylet and cannula in order for the biopsyneedle to be inserted into the biopsy gun. However, this task ofinserting the biopsy needle into the biopsy gun while the connectingelements are maintained in a fixed orientation is difficult because thestylet is generally freely displaceable in the cannula. Therefore, it isgenerally necessary to align the connecting elements of the biopsyneedle, either manually or through use of a separate spacer, prior toinsertion into a biopsy gun.

After the biopsy needle is inserted into a biopsy gun, if a spacer clipis used, it is generally necessary to remove the spacer in order toclose the lid and operate the biopsy gun. Conventional spacer clipsrequire the molding of a separate spacer. This requirement of a separatemolding step adds an additional step in the manufacturing and packagingprocess thereby increasing the costs to produce the biopsy needle.Moreover, the use of a separate spacer clip may require undue handlingof the needle in order to connect and disconnect the spacer clip.Furthermore, some conventional biopsy guns do not permit the option ofinserting the needle into a biopsy gun in the uncocked position. Bypermitting a biopsy needle to be inserted in an uncocked biopsy gun, theproper operation of the needle is checked prior to the gun being firedby moving the inner needle and the outer needle relative to each otherduring the cocking process. An additional disadvantage of someconventional biopsy needles is that under some conditions, theindividual connecting elements slip or rotate relative to the slidesthey are carried on when inserted in a biopsy gun.

While some prior integrated spacers have addressed many of theseproblems by fixing the relationship between the hubs and needles, it isbelieved that some of them achieve these benefits at the expense ofcreating drag on the hubs during firing. Since these prior integratedspacers require a tight friction fit with the hubs, movement of the hubswithin the gun may be compromised. Therefore, a need remains forimproved integrated spacers.

SUMMARY OF THE DISCLOSURE

The present invention includes a biopsy needle particularly suited foruse in a biopsy gun. The invention includes an integrated guide pin anda stop engagement. The guide pin stop engagement prevents disengagementof the cannula and the stylet, facilitates needle alignment without theuse of extrinsic devices and prevents rotation and other movement of theinner and outer needles relative to each other and the slides in abiopsy gun. Additionally, the integrated design of the needle allows theneedle to be easily prepackaged in a sterile, disposable condition.

Other features and advantages of the present invention will becomereadily apparent from the following detailed description, the appendedclaims and the accompanying drawings. It is to be understood that boththe foregoing general description and the following detailed descriptionare exemplary and provided for purposes of explanation only, and are notrestrictive of the invention, as claimed.

BRIEF DESCRIPTIONS OF DRAWINGS

FIG. 1 is a side elevational view of a biopsy needle according to thisinvention.

FIG. 2 is a top perspective view of a biopsy needle of this inventionshown in the first position.

FIG. 3 is a top perspective view of the needle of FIG. 2 shown in thesecond position.

FIG. 4 is a partial bottom perspective view of second hub of the needleof FIG. 2 shown approaching the second position.

FIG. 5 is a partial bottom perspective view of second hub of the needleof FIG. 2 shown in the second position.

FIG. 6 is a side view of a portion of the second hub showing therelationship between the ramp and the stop member.

FIG. 7 is an isometric view of one embodiment of the biopsy needle ofthe present invention used in conjunction with a biopsy gun of a typethat is well-known in the art.

Although the drawings represent embodiments of the present invention,the drawings are not necessarily to scale and certain features may beexaggerated in order to better illustrate and explain the presentinvention. The exemplification set out herein illustrates certainembodiments of the invention, in one, or more forms, and suchexemplifications are not to be construed as limiting the scope of theinvention in any manner.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

For the purposes of promoting an understanding of the principles of theinvention, reference will now be made to the embodiments illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of theinvention is thereby intended. The invention includes any alterationsand further modifications in the illustrated devices and describedmethods and further applications of the principles of the invention thatwould normally occur to one skilled in the art to which the inventionrelates.

The present invention provides a biopsy needle having an integratedguide pin and a stop engagement. A preferred embodiment of a biopsyinstrument 10 for use in a biopsy gun of this invention is shownschematically in FIG. 1. Instrument 10 includes a hollow outer needle 12having a proximal end 14 and a distal end 16 and defining a lumentherethrough. An inner needle 20 is slidably engaged within the lumen. Afirst hub 30 is attached to the proximal end 22 of the inner needle. Asecond hub 35 is attached to the proximal end 14 of the outer needle 12.

The first hub 30 defines a longitudinally extending bore 32 for holdingthe proximal end 22 of inner needle 20. Bore 32 may extend through theentire length of the first hub 30, however it is not necessary so longas the proximal end 22 of inner needle is securely attached. Hub 30 alsoincludes means for engaging the carriage of a biopsy device. In someembodiments, the means includes a vertically extending bore 31 as shownin FIG. 1. The second hub 35 may be identical to the first hub 30,except that the longitudinally extending bore 37 should extend throughthe entire length of the second hub 35. The longitudinally extendingbore 37 of the second hub 35 holds the proximal end 14 of the outerneedle 12.

For purposes of ease of manufacture, hubs 30, 35 may be identical. Thehubs 30, 35 may be formed by insert molding and other techniques thatare known in the art. According to one way of making the invention, thehubs 30, 35 are insert molded around inner needle 20 and outer needle12, respectively. It should be noted that although the preferredembodiment illustrates vertically extending bores 31, 36 in the hubs 30,35 for engagement to the slides of a biopsy gun, other configurationsmay be used, such as, for example, flanges.

The hubs 30, 35 are moveable/slideable relative to one another between afirst position shown in FIG. 2 wherein the distal end 24 of the innerneedle 20 is retracted within the lumen and a second position shown inFIG. 3. In the second position, the distal end 24 of the inner needle 20is extended away from the outer needle 12 to expose a cavity 25 definedadjacent the distal end 24 of the inner needle 20. In the firstposition, the cavity 25 is covered by the outer needle 12.

The design of the outer needle 12 and the inner needle 20 is generallywell known in the art, and one or both may have a beveled cutting edge17, 26 on their distal ends 16, 24, respectively. The inner needle 20and the outer needle 12 may be of a variety of gauge sizes. The gaugeand length of the inner needle and outer needle varies with theprocedure for which it will be used. In particular embodiments, theneedles are provided in lengths between 10 cm to 29 cm and gauge sizesof 20 gauge to 12 gauge.

An elongated pin 50 is provided to maintain proper relationships betweenthe hubs 30, 35. The first end 53 of the pin 50 is fixedly attached tothe first hub 30. In one particular embodiment, pin 53 is engaged withina second longitudinal bore 33 defined through first hub 30 (FIG. 1).Second hub 35 and the pin 50 are slideable or moveable relative to eachother, or in other words, second hub 35 is moveable relative to the pin50 between the first and second ends 53, 56. The length of the pin maybe configured to allow the biopsy needle 10 of the present invention tobe used in various biopsy guns.

A stop engagement is provided between the second end 56 of the pin 50and the second hub 35, which prevents disengagement of the outer andinner needles 12, 20. In some embodiments, the stop engagement involvesan engagement member at the second end 56, which is configured to engagethe second hub 35 when the second hub 35 is at the second end 56 of pin50.

Referring now to FIGS. 2-5, details of one embodiment of the stopengagement are provided. In a specific embodiment, a track 38, whichruns parallel to the outer needle 12, is provided on the second hub 35.The track 38 may be defined by the surface 41, a wall member 44projecting from the surface 41 and a dog 46 projecting from the wall 44.Pin 50 is slidably disposed within track 38. The shaft 54 of pin 50 runsparallel to the needles 12, 20, and the second hub 35 is slideable alongthe pin 50 between a location 58 near the first end 53 and the secondend 56.

In a specific embodiment, a stop member 60 projects from surface 41 ofthe second hub 35 adjacent the track 38. The engagement member engagesthe second hub 35 at the stop member 60. In this embodiment, theengagement member is an arm 55 projecting from the second end 56 of thepin 50. In a specific embodiment, arm 55 is formed from a bend in pin50. However, any suitable means of creating arm 55 is contemplated.

Referring now to FIGS. 4-6, the embodiment shown further includes a ramp70 projecting from the surface 41 at a location distal to the stopmember 60. Ramp 70 is inclined towards stop member 60. Ramp 70 includesa ramp head 72 facing stop member 60. The space 80 between ramp 72 andstop member 60 has a length L that is at least as large as a crosssectional dimension of said arm 55. In embodiments wherein arm 55 istubular, the cross sectional dimension is the diameter D. Stop member 60has a height H that is sufficient to prevent arm 55 to roll over stopmember during operation of the device 10. Ramp has a height h sufficientto prevent the arm 55 from backing over the ramp 70 as the biopsyinstrument 10 is inserted into the biopsy gun. In one specificembodiment, ramp 70 has a height h of at least about one third of theheight of the arm 55. When arm 55 is tubular, the height will be thediameter D. In one specific embodiment, ramp 55 has a height Dsufficient to provide a tactile indication when arm 55 slides over ramp70 and into said space 80.

Some embodiments of the biopsy needle 10 of this invention provideseveral advantages over conventional biopsy needles and even thoseconventional biopsy needles that employ separate and integral spacerclips. When the biopsy needle 10 of the present invention is in thefirst position as shown in FIG. 5, the first and second hubs 30, 35 arein the maximally displaced position. With the arm 55 within space 80,the user may easily insert the biopsy needle 10 into the gun withoutmoving the position of the hubs 30, 35 relative to each other. In thisposition, the distance between the vertical bores 31, 36 is sufficientto align these holes with posts located on the slides of a cocked biopsygun. In addition the hubs, and therefore the needles, are kept in properrotational alignment.

Therefore, biopsy needle 10 can be loaded into a biopsy gun withoutmanipulation of the hubs 30, 35. Moreover, while some integrated spacerdevices provide these same advantages, it is believed that some of themachieve these benefits at the expense of creating drag on the hubsduring firing. Since these prior integrated spacers require a tightfriction fit with the hubs, movement of the hubs within the gun may becompromised.

The biopsy needle 10 of this invention can be inserted into a biopsy guneither in the cocked or uncocked position to accommodate the user'spreference. The pin 50 also facilitates removal of the biopsy needle 10from a biopsy gun without the necessity to reattach a spacer clip as isrequired with some prior biopsy needles. If the biopsy needle 10 isinserted while the gun is uncocked, the gun should be cocked prior touse.

The device 10 can be shipped in the second position (FIG. 3) with thehubs 30, 35 close together. Insertion of the biopsy needle 10 into abiopsy gun 90 is generally straight forward as shown in FIGS. 4, 5 and7. The user moves the second hub 35 away from the first hub 30 towardsthe distal end 16, which moves the outer needle 12 to cover the cavity25 of inner needle 20. As the second hub 35 travels forward in thedirection of arrow F in FIG. 4, arm 55 encounters the ramp 70 andtravels over the incline and into the space 80 and contacts the stopmember 60. At this point, the user feels a definite click. This tactileindicator tells the user that the device is in position to be loaded.

The device is now in the first position shown in FIG. 2. The outerneedle 12 is positioned over cavity 25, the beveled tip 26 of innerneedle 20 is exposed, and the rotational relationship of the hubs and,as a result, the needle cavity and beveled tips, is fixed. When thefirst and second hubs 30, 35 are maximally displaced relative to eachother in the first position, the distance between the bore 31 in thefirst hub 30 and the bore 36 in the second hub 35 is such that thebiopsy needle 10 can be inserted with the proper spacing into a biopsygun in the cocked position as shown in FIG. 7. The hubs 30, 35 are alsoin proper orientation for operation of the gun 90. This eliminates theneed for any external means of achieving the proper spacing of theneedle. Alternatively, the needle can be mounted in a biopsy gun in theuncocked position.

One of the hubs is grasped by the user and placed over the interiorchamber of the biopsy gun 90, as illustrated in FIG. 7. Verticallyextending bores 31, 36 of the first and second hubs 30, 35 are alignedover the slides 91, 92 of the biopsy gun 90 and receive posts 93, 94,respectively. Without having to remove the integrated pin 50, the lid 95to the biopsy gun 90 is closed and is ready for use.

In some embodiments, the tip 26 of inner needle 20 is exposed tofacilitate insertion of the biopsy needle 10 into the tissue beingsampled. After tip 26 is properly positioned within the tissue, thebiopsy gun is then triggered causing the first hub 30 and the pin 50 tomove forward towards the distal end in the direction of arrow F, whilethe second hub 35 is held stationary. This movement causes the innerneedle 20 to move forward into the tissue being sampled and exposes thecavity 25, which receives the tissue to be sampled. The device is now inthe second position depicted in FIG. 3. For the pin 50 to move, the arm55 must overcome the ramp head 72 to move out of space 80. While the arm55 will not back out over the ramp 70 during loading of the gun 90, theforce of the gun 90 is more than sufficient to smoothly overcome theramp head 72 without interfering with the action of the gun 90.

The second slide 92 of the biopsy gun 90 is then triggered moving thesecond hub 35 forward in the direction of arrow F. This action causesthe outer needle 12 to move forward over cavity 25, which causes outerneedle 12 to separate and trap tissue prolapsed in the cavity 25. Atthis point, the device 10 has returned to the first position shown inFIG. 2 with the arm 55 in the space 80 (FIG. 5). The biopsy needle 10can then be removed and the tissue examined. The pin 50 in engagementwith the first and second hubs 30, 35 during operation of the biopsy gun90, stabilizes the first and second hubs 30, 35 and prevents twistingand bending in the biopsy gun 90. The hubs 30, 35 are fixed rotationallyrelative to one another due to the fixed connection of the first end 53of the pin 50 within the longitudinal bore 33 of the first hub 30 andthe cooperation of the longitudinal bore 33, the track 38, and the dog46 to prevent rotation of the hubs 30, 35 relative to each other.

Other embodiments of the invention will be apparent to those skilled inthe art from consideration of the specification and practice of theinvention disclosed herein. For example, in another embodiment, arm 55engages another portion of the second hub 35, such as wall member 48. Inthis embodiment, pin 50 is rotated 180°, and the stop member 60 is notrequired. It is intended that the specification, drawings and examplesbe considered as exemplary only, with the true scope and spirit of theinvention being indicated by the following claims. It should beunderstood that only the preferred embodiments have been shown anddescribed and that all changes and modifications that come within thespirit of the invention are desired to be protected.

1. A biopsy instrument for use in a biopsy gun, comprising: a hollowouter needle having a proximal end and a distal end and defining a lumentherethrough; an inner needle slidably disposed within said lumen, saidinner needle having a proximal end and a distal end and defining acavity adjacent said distal end for receiving a tissue sample; saidinner and outer needles slideable relative to one another between afirst position wherein said distal end of said inner needle is retractedwithin said lumen so that said outer needle covers said cavity and asecond position wherein said distal end of said inner needle is extendedaway from said outer needle to expose said cavity; a first hub attachedto said proximal end of said inner needle; a second hub attached to saidproximal end of said outer needle, said second hub having a trackrunning parallel to said outer needle and a stop member projecting froma surface of said second hub adjacent said track, wherein said track isdefined by said surface, a wall projecting from said surface and a dogprojecting from said wall; and an elongated pin having a first end, asecond end and an arm projecting from said second end, said first endfixedly attached to said first hub with said shaft parallel to saidinner needle and said pin slidingly engaged to said second hub withinsaid track, said second hub slideable along said pin between a locationnear said first end and said second end where said arm meets said stopmember.
 2. The biopsy instrument of claim 1 wherein said second hub isslideable along said pin a distance sufficient to enable operation ofthe biopsy instrument in a biopsy gun.
 3. The biopsy instrument of claim1 wherein said second hub is slideable along said pin a predetermineddistance to enable insertion of said biopsy needle in a biopsy gun. 4.The biopsy instrument of claim 1 further comprising a ramp projectingfrom said surface at a location distal to said stop member, said rampinclined towards said stop member.
 5. The biopsy instrument of claim 4wherein said ramp includes a ramp head facing said stop member, saidramp head and said stop member defining a space, said space having alength that is at least as large a cross sectional dimension of saidarm.
 6. The biopsy instrument of claim 5 wherein said ramp has a heightsufficient to prevent said arm from backing over said ramp as the biopsyinstrument is inserted into the biopsy gun when said arm is positionedin said space.
 7. The biopsy instrument of claim 6 wherein said ramp hasa height of at least about one third of a height of said arm.
 8. Thebiopsy instrument of claim 6 wherein said ramp has a height sufficientto provide a tactile indication when said arm slides over ramp and intosaid space.
 9. The biopsy instrument of claim 6 wherein said track isdefined by said surface, a wall projecting from said surface and a dogprojecting from said wall.
 10. A biopsy instrument for use in a biopsygun, comprising: a hollow outer needle having a proximal end and adistal end and defining a lumen therethrough; an inner needle slidablydisposed within said lumen, said inner needle having a proximal end anda distal end; a first hub attached to said maximal end of said innerneedle; a second hub attached to said proximal end of said outer needle;an elongated pin having a first end and a second end, said first endfixedly attached to said first hub and said pin in sliding contact withsaid second hub so that said second hub is moveable relative to said pinbetween said first end and said second thereof, said elongated pinincluding an engagement member at said second end configured to engagesaid second hub when said second hub is at said second end; and a rampprojecting from a surface at a location distal to stop member, said rampinclined towards said stop member.
 11. The biopsy instrument of claim 10wherein one of said first and second hubs is slideable relative to theother of said first and second hubs to a position wherein a distancebetween said first hub and said second hub is sufficient to enableoperation of the biopsy instrument in a biopsy gun.
 12. The biopsyinstrument of claim 10 wherein one of said first and second hubs isslideable relative to the other of said first and second hubs to aposition wherein a distance between said first hub and said second hub apredetermined distance to enable insertion of said biopsy needle in abiopsy gun.
 13. The biopsy instrument of claim 10 wherein saidengagement member is an arm projecting from said second end of said pin.14. The biopsy instrument of claim 13 wherein said engagement memberengages said second hub at a stop member projecting from a surface ofsaid second hub.
 15. The biopsy instrument of claim 14, wherein saidsecond hub defines a track running parallel to said outer needle andsaid pin is slideable within said track.
 16. The biopsy instrument ofclaim 15 wherein said stop member is adjacent said track.
 17. The biopsyinstrument of claim 10 wherein said ramp includes a ramp head facingsaid stop member, said ramp head and said stop member defining a space,said space having a length that is at least as large as a crosssectional dimension of said arm.
 18. The biopsy instrument of claim 17wherein said ramp has a height sufficient to prevent said arm frombacking over said ramp as the biopsy instrument is inserted into thebiopsy gun when said arm is positioned in said space.
 19. The biopsyinstrument of claim 18 wherein said ramp has a height of at least aboutone third of a height of said arm.
 20. The biopsy instrument of claim 18wherein said ramp has a height sufficient to provide a tactileindication when said arm slides over ramp and into said space.
 21. Thebiopsy instrument of claim 18 wherein said track is defined by saidsurface, a wall projecting from said surface and a dog projecting fromsaid wall.
 22. The biopsy instrument of claim 21 wherein said first hubdefines a longitudinal bore said first end of said pin is fixedlyattached within said longitudinal bore, said longitudinal bore, saidtrack and said dog cooperating to prevent rotational movement of saidhubs relative to each other.